miR-17-5p靶向B7-H3对结直肠癌细胞生物学特性及免疫调节作用的影响

Effects of miR-17-5p targeting B7-H3 on biological characteristics and immunomodulatory effects of colorectal cancer cells

目的:探究miR-17-5p对B7-H3的调控以及在结直肠癌发展中的免疫调节作用。方法:收集25例人结直肠癌组织及相邻正常组织,通过实时荧光定量PCR、蛋白免疫印迹和免疫组化实验分析miR-17-5p、B7-H3和PD-L1的表达水平。将人结直肠癌HCT-116细胞分为4组:miR-NC组、miR-17-5p mimic组、si-NC组、si-B7-H3组。通过细胞集落形成实验、Transwell实验和流式细胞术分析HCT-116细胞生长、侵袭能力和凋亡率。通过荧光素酶报告基因实验分析miR-17-5p对B7-H3的调控作用。通过ELISA实验分析细胞培养液中IL-2、IL-4、IL-6、IL-10、IFN-γ及TNF-α的细胞因子水平。结果:与癌旁组织比较,结直肠癌组织中miR-17-5p表达下降,B7-H3表达升高。miR-17-5p mimic和si-B7-H3能够降低HCT-116细胞集落形成数量和侵袭数量,促进HCT-116细胞凋亡,并能降低培养液中IL-2、IL-4、IL-6、IL-10、IFN-γ及TNF-α水平。此外,miR-17-5p mimic和si-B7-H3能够抑制HCT-116细胞PD-L1表达。结论:miR-17-5p能够靶向抑制B7-H3表达,影响结直肠癌发展中的免疫调节作用,并能抑制结直肠癌细胞的转移,促进结直肠癌细胞凋亡。

Objective:To investigate the regulatory role of miR-17-5p on B7-H3 and its immunomodulatory role in the development of colorectal cancer.Methods:Twenty-five pairs of human colorectal cancer tissues and adjacent normal tissues were collected,and the expression levels of miR-17-5p,B7-H3 and PD-L1 were analyzed by real-time fluorescence quantitative PCR,protein immunoblotting and immunohistochemical assays.Human colorectal cancer HCT-116 cells were divided into four groups:miR-NC group,miR-17-5p mimic group,si-NC group and si-B7-H3 group.The growth,invasive ability and apoptosis rate of HCT-116 cells were analyzed by cell colony formation assay,Transwell assay and flow cytometry.The regulatory effect of miR-17-5p on B7-H3 was analyzed by luciferase reporter gene assay.The levels of IL-2,IL-4,IL-6,IL-10,IFN-γand TNF-αcytokines in the cell culture medium were analyzed by ELISA.Results:Compared with paracancerous tissues,miR-17-5p expression was decreased and B7-H3 expression was increased in colorectal cancer tissues.miR-17-5p mimic and si-B7-H3 were able to reduce the number of HCT-116 cell colony formation and invasion,promote HCT-116 cell apoptosis,and decrease the levels of IL-2,IL-4,IL-6,IL-10,IFN-γand TNF-αcytokines in culture medium.In addition,miR-17-5p mimic and si B7-H3 were able to inhibit PD-L1 expression in HCT-116 cells.Conclusion:miR-17-5p can targeting inhibit B7-H3 expression,affect the immunomodulatory role in colorectal cancer development,and inhibit metastasis and promote apoptosis of colorectal cancer cells.